Take a look at the latest Presidential Order that relates to strengthening cybersecurity that relates to critical infrastructure:

https://www.whitehouse.gov/presidential-actions/presidential-executive-order-strengthening-cybersecurity-federal-networks-critical-infrastructure/

Let’s look at a real-world scenario and how the Department of Homeland Security (DHS) plays into it. In the scenario, the United States will be hit by a large-scale, coordinated cyber attack organized by China. These attacks debilitate the functioning of government agencies, parts of the critical infrastructure, and commercial ventures. The IT infrastructure of several agencies are paralyzed, the electric grid in most of the country is shut down, telephone traffic is seriously limited and satellite communications are down (limiting the Department of Defense’s [DOD’s] ability to communicate with commands overseas). International commerce and financial institutions are also severely hit. Please explain how DHS should handle this situation.
please explain how DHS should handle the situation described in the preceding paragraph.